content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2011, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
   * Other names may be trademarks of their respective owners.]
   *
   * ------------------
   * KeyedValues2D.java
   * ------------------
   * (C) Copyright 2002-2008, by Object Refinery Limited.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * Changes
   * -------
   * 28-Oct-2002 : Version 1 (DG);
   * 12-Jan-2005 : Updated Javadocs (DG);
   *
   */
  
  package org.jfree.data;
  
  import java.util.List;
  
  /**
   * An extension of the {@link Values2D} interface where a unique key is
   * associated with the row and column indices.
   */
  public interface KeyedValues2D extends Values2D {
  
      /**
       * Returns the row key for a given index.
       *
       * @param row  the row index (zero-based).
       *
       * @return The row key.
       *
       * @throws IndexOutOfBoundsException if <code>row</code> is out of bounds.
       */
      public Comparable getRowKey(int row);
  
      /**
       * Returns the row index for a given key.
       *
       * @param key  the row key.
       *
       * @return The row index, or <code>-1</code> if the key is unrecognised.
       */
      public int getRowIndex(Comparable key);
  
      /**
       * Returns the row keys.
       *
       * @return The keys.
       */
      public List<Comparable> getRowKeys();
  
      /**
       * Returns the column key for a given index.
       *
       * @param column  the column index (zero-based).
       *
       * @return The column key.
       *
       * @throws IndexOutOfBoundsException if <code>row</code> is out of bounds.
       */
      public Comparable getColumnKey(int column);
  
      /**
       * Returns the column index for a given key.
       *
       * @param key  the column key.
       *
       * @return The column index, or <code>-1</code> if the key is unrecognised.
       */
      public int getColumnIndex(Comparable key);
  
      /**
       * Returns the column keys.
       *
       * @return The keys.
       */
      public List<Comparable> getColumnKeys();
  
      /**
       * Returns the value associated with the specified keys.
       *
       * @param rowKey  the row key (<code>null</code> not permitted).
       * @param columnKey  the column key (<code>null</code> not permitted).
       *
       * @return The value.
       *
       * @throws UnknownKeyException if either key is not recognised.
       */
      public Number getValue(Comparable rowKey, Comparable columnKey);
  
  }
  